Raiders cut receiver Antonio Brown; he lands with...

1of4Antonio Brown reportedly signed a one-year, $15 million deal with the Patriots that includes a $9 million signing bonus.Photo: Christian Petersen / Getty Images

2of4Head coach Jon Gruden (left) said Saturday that Brown would play Monday, days after a heated clash with general manager Mike Mayock a cracker.Photo: Don Juan Moore / Getty Images

3of4Antonio Brown has 100 or more catches in each of his last six seasons, the only receiver in NFL history with a streak that long. He also exceeded 1,200 receiving yards in each of those seasons.Photo: Patrick Smith / Getty Images

4of4FILE - In this Aug. 20, 2019, file photo, Oakland Raiders' Antonio Brown walks off the field after NFL football practice in Alameda, Calif. Star receiver Antonio Brown is not with the Oakland Raiders four days before the season opener amid reports he could be suspended over a confrontation with general manager Mike Mayock. Mayock issued a brief statement at the beginning of practice Thursday, Sept. 5, 2019, saying that Brown wasn't at the Raiders facility and won't be practicing a day after Brown posted a letter from the GM on social media detailing nearly $54,000 in fines. (AP Photo/Jeff Chiu, File)Photo: Jeff Chiu / Associated Press

On Friday morning, Raiders head coach Jon Gruden told reporters he expected receiver Antonio Brown to play in Monday night’s season opener against the Broncos.

Less than 24 hours later, the Raiders released Brown, a four-time All-Pro, delivering the news publicly in a one-sentence statement.

And then, five hours later, Brown reportedly agreed to sign with the New England Patriots.

It was a jarring end to a tumultuous six months between Brown and the Raiders, who acquired Brown from Pittsburgh in March and signed him to a three-year contract worth more than $50 million with $30 million in guarantees.

Ultimately, Brown never played a snap for the Raiders, even in the preseason.

ESPN reported Brown had agreed to a one-year, $15 million deal with the Patriots that includes a $9 million signing bonus. Brown is not eligible to play in the Patriots’ season opener but could join New England in Week 2.

Brown had been set to earn $14.6 million in base salary in 2019 with the Raiders. But his exit was hastened Saturday by the Raiders reportedly looking to void his guaranteed money.

On Friday, the Raiders fined Brown for conduct this week that included confronting general manager Mike Mayock over nearly $54,000 in previous fines at training camp. ESPN reported the Raiders fined Brown more than $215,000 for conduct detrimental to the team — thereby voiding $29.1 million of guarantees in Brown’s contract.

After the Raiders practiced Saturday, Gruden was asked what had led to Brown’s release.

“We just have exhausted everything,” Gruden said. “We tried every way possible to make it work. And all I’m going to say is, it’s disappointing. I’m really proud — really proud of our players, our coaches, our owner, our front office. We did everything we could to make this work. And I’m sorry it didn’t. I apologize.

“But I will tell you I am very proud of what we did as an organization to try. And I wish Antonio nothing but the best. And I’m sorry that we never got a chance to see him in silver and black — very disappointing in my career as a coach. I really looked forward to coaching him. But it’s not going to happen.”

The Raiders acquired Brown from the Steelers for third- and fifth-round draft picks after Brown had publicly voiced his desire to leave Pittsburgh.

At a news conference introducing Brown on March 13, Gruden said he believed the Raiders had “acquired the best receiver in football.” Brown, meanwhile, vowed to bring “accountability” to the Raiders and their receiver group.

“I bring actions,” Brown said. “Not what I say, what I do, how I approach things.”

In July, Brown announced his arrival at Raiders training camp in Napa on a hot-air balloon ride. But he missed much of camp and the preseason between recovering from frostbite on his feet, the result of a cryotherapy mishap, and a dispute with the NFL over helmet rules.

On Aug. 18, with Brown absent from practice amid the helmet dispute, Mayock issued a public ultimatum that it was time for Brown to be “all in or all out” with the Raiders. Brown was back with the team the next day and began practicing shortly thereafter.

Tensions between Brown and the Raiders rose this week, with Brown confronting Mayock and the Raiders reportedly considering a suspension for the receiver. On Friday, Brown was at the team’s Alameda facility and issued an apology in a team meeting. A day later, Brown was no longer a Raider.

“It was a series of things,” Gruden said after practice Saturday. “I just don’t think it worked. It didn’t fit here. He would have to answer that for himself, and I’m sure he will. … I’m sorry to all the Raider fans. But again, I really want to thank our football players, (owner) Mark Davis and all of us. We did try to make it work. And hopefully he finds what he’s looking for.”

On Friday evening, Brown posted a video on YouTube that appeared to include audio recorded from a phone conversation between him and Gruden. It includes an exchange in which Gruden says to Brown: “Please stop this s— and just play football.”

Brown is the only receiver in NFL history with six straight seasons of 100 or more receptions, and he also exceeded 1,200 receiving yards in each of his last six seasons with the Steelers. The Raiders acquired Brown to be a crucial part of their offense as they attempt to improve on a four-win 2018 record in their likely final season in Oakland before moving to Las Vegas.

Instead, the Raiders were left turning their focus Saturday toward preparing without Brown for their season opener in two days. As players spoke of moving on without Brown after practice Saturday, Brown’s signing with New England had not yet been reported.

“A.B., he’s our teammate, hate to see him gone,” linebacker and captain Vontaze Burfict said. “Praying for him. Hopefully he can get everything cleaned up. He’s a great football player. But like I’ve said, we’re worried about Monday.”